title: The human WBSCR22 protein is involved in the biogenesis of the 40S ribosomal subunits in mammalian cells.
abstract: The human WBSCR22 protein was previously shown to be up-regulated in invasive breast cancer and its ectopic expression enhances tumor cell survival in the vasculature. In the current study, we show that the WBSCR22 protein is important for cell growth. Knock-down of WBSCR22 with siRNA results in slower growth of WBSCR22-depleted cells. Treatment with siWBSCR22 causes defects in the processing of pre-rRNAs and reduces the level of free 40S ribosomal subunit, suggesting that WBSCR22 is involved in ribosome small subunit biosynthesis. The human WBSCR22 partially complements the growth of WBSCR22 yeast homologue, bud23 deletion mutant suggesting that the human WBSCR22 is a functional homologue of yeast Bud23. WBSCR22 is localized throughout the cell nucleus and is not stably associated with ribosomal subunits within the cell nucleus. We also show that the WBSCR22 protein level is decreased in lymphoblastoid cell lines derived from William-Beuren Syndrome (WBS) patients compared to healthy controls. Our data suggest that the WBSCR22 protein is a ribosome biogenesis factor involved in the biosynthesis of 40S ribosomal particles in mammalian cells.
authors.affiliation: Center of Biomedical Technology, Institute of Technology, University of Tartu, Tartu, Estonia.
authors.forename: Kadri
authors.initials: K
authors.lastname: Õunap
authors.forename: Ly
authors.initials: L
authors.lastname: Käsper
authors.forename: Ants
authors.initials: A
authors.lastname: Kurg
authors.forename: Reet
authors.initials: R
authors.lastname: Kurg
mesh_terms: D002460:Cell Line; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D008780:Methyltransferases / Q000235:genetics* / Q000378:metabolism*; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism; D054682:Ribosome Subunits, Small, Eukaryotic / Q000235:genetics* / Q000378:metabolism*; D017384:Sequence Deletion / Q000235:genetics; D015003:Yeasts / Q000235:genetics / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D012322:RNA Precursors; C455827:BUD23 protein, human; D008780:Methyltransferases